During the lifespan of an ink jet pen containing one or more printheads, ink mist, dried ink and debris from the print media tend to accumulate on the nozzle plates of the printheads adjacent orifice holes therein. If not removed, the debris may accumulate to the point it blocks or partially blocks ejection of ink from the nozzle holes. Periodically, therefor, it is necessary to remove the debris from adjacent the nozzle holes so that the performance of the pen will not be impaired. Cleaning of the nozzle plates may be conducted using solvents or preferably by passing a flexible wiper across the nozzle plate to loosen and remove ink mist, dried ink and debris such as paper fibers therefrom. A wide variety of wipers and wiper blade designs are used for cleaning ink jet printhead nozzle plates.
In order to effectively clean a nozzle plate of a printhead with a wiper device, the pen must have a structure or configuration which lends itself to effective wiping across the nozzle plate or plates of the printheads. A single color ink jet pen contains a single printhead and a flexible circuit connected to a silicon substrate containing heater resistors and control devices for selectively ejecting ink from one or more nozzle holes of the printhead. Typically, the flexible circuit surrounds the nozzle plate or is integrally formed with the nozzle plate and is attached to a printhead carrier structure or pen body in a recessed portion therein. The raised sides of the pen body are often sufficient to protect the wiper from the relatively sharp edges of the flexible circuit as the wiper traverses the nozzle plate during a cleaning operation.
As contrasted with a single color ink jet pen, a multi-color pen contains multiple nozzle plates and associated flexible circuits for the printheads thereof. Typically, only the raised portions of the pen body adjacent the outermost edges of the flexible circuits protect the wiper as the blade of the wiper traverses the nozzle plates. It is difficult to adequately protect the wiper from interior edge portions of the flexible circuits remote from the raised portions of the pen body between adjacent nozzle plates because of printhead spacing tolerances. Thus these interior portions of the flexible circuits are often exposed. During a cleaning operation, as the flexible wiper blade traverses across the printhead surface of the pen body, the exposed edges of the flexible circuits can damage and/or cause excessive wear on the wiper.